Quick Question on Over-, WayOver- and fistLayer Underextrusion  

Quick Question on Over-, WayOver- and fistLayer Underextrusion

Hello People, 

I'm currently in the process of adjusting the print settings for my Tripodmaker-turned-Duet2 printer. Have used SimplyFy3D so far, but that Interface is a mess and they charge for every update. To the contrary, with PrusaSlicer I can send the print to my Duet directly, without saving the GCODE, uploading it and only then running it. So the Prusaslicer is really a great piece of software, thank you team 🙂 

Below you can see two of my first gruesome prints and glue remains. Nevermind the quality, but here's what puzzles me: The left print is obviously WAY over-extruded, but the first layer looks good. The second print is still over-extruded, but the first layer is clearly UNDER-extruded. With my settings, I can't see why this would happen. 

left is WAY over-extruded, right is just over-extruded

left 1st layer is ok, right is underextruded

General:

• 1mm nozzle
• ABS, 255°C
• 2 perimeters
• walll thickness of the upper part of the print: 2mm

1st print settings: 

• Default extrusion width: 1mm
• Extrusion width - First layer: 120%
• Extrusion multiplier: 100% 

2nd print settings:

• Default extrusion width: 1mm
• Extrusion width - First layer: 120%
• Extrusion multiplier: 85% 

I'm assuming it has less to do with the above mentioned settings. A little bit of the same effect I had already with Simplify3D, but no way as strong. The prints were usually okayish. But this time I don't want to fiddle&fix the settings for every print, but rather use the PrusaSlicers clean and understandable settings to adjust the material and the printer independently properly, once and for all. 

Any ideas where this curious behavior might come from are welcome. 

PS to the moderators: my images are showing up in the editor, but not in the post. Weird, huh? Can u fix? Thanks!